Horicultural oils smother out pests

By Tom Dominguez, Quay County Extension

Now is a good time to control scale insects on evergreen shrubs and trees such as camellias, hollies, bay laurel, myrtle, enonymus, citrus, photinias and boxwood through use of a horticultural oil spray.

Fruit trees may be sprayed at this time of year in order to control insect eggs that may have been laid in bark and twig crevices.
Usually, the oil treatment will need to be applied only once a year, and is an excellent way to smother a pest that is difficult to eradicate. At times even live oaks fall prey to scale, but due to difficulties of size these plants are much harder to work with.

Horticultural oils also have the benefit of being less environmentally harsh than pesticides.

Trees and shrubs are often unable to withstand the continual drain of sap from these sucking insects, and may ultimately be killed.

Treatment consists of thoroughly spraying with horticultural oil according to directions, from every direction over the leaves and twigs.

There are several thousand species of “scale insects”. Armored scale insects are capable of navigating to fresh feeding grounds when very small, but then live and feed under a protective hard, waxy shield as adults. Tea scales, oyster scales, eunonymous scales and wax